Also check your oneway bearing. Last week a friend had the same problem after a crash. He replaced his main gear. (striped gears)
When he put the oneway back into the new main gear he didn't put the bearing in low enough so this caused a slight rubbing between main gear and tail gear. I didn't think this would have anything to with bad blade tracking. So I told him to check a few things like making sure the flybar holder is level/flat as possible, blades are tighten the same. He started at the oneway and push it down more into the main gear. Took it out to test it and NO more tracking problem. Tracking is on the money now. Strange but it works.